Background Venous thromboembolism (VTE) is a common complication during and after a hospital admission. That is associated with significant morbility and mortality after orthopedic surgery. The ACCP Guidelines showed that limb or hip joint orthopedic surgery itself was one of the risk factors for VTE. To avoid the development of VTE after orthopedic surgery, it is essential to reduce the onset of deep vein thrombosis (DVT) and to diagnose DVT early. The clinical signs and symptoms of DVT are unreliable. It leads to early diagnosis to find a risk factor of DVT from medical history of the patient. However, the risk for preoperative DVT in patients for hip joint orthopedic surgery remains unclear. We, therefore, decided to study the risk of DVT in patients admitted to hospital for total hip arthroplasty (THA).

Objectives The objective of this study was to investigate the risk of DVT in patients admitted to hospital for THA.

Methods Patients: From September of 2003 to December of 2010, 505 patients with preoperative THA at our institution were eligible for the present study. The surgical diagnosis was degenerative osteoarthritis (OA) in 361 patients, rheumatoid arthritis (RA) in 31 patients, osteonecrosis in 27 patients, fracture and bone tumor in 2 patients, and failure of prosthesis in 82 patients. We recorded that data on medical history, medical condition and the potential risk factors for VTE, including age and BMI.

Diagnosis of DVT: B-mode ultrasonography with compression and color Doppler imaging were performed for bilateral common femoral veins, the superficial veins, the popliteal veins, and the calf veins.

Statistical analysis: We compared the patients' preoperative characteristics between DVT positive and negative using the Mann–Whitney U test and Fisher's exact test. A multiple linear regression analysis was performed to identify risk factors that were independently associated with preoperative DVT.

Results The main preoperative diagnosis for patients was OA (71.5%). Moreover, most admissions for joint replacement in our population were for primary procedures (83.8%). The most frequent preoperative medical history or medical condition was major surgery including primary THA and cancer (37.0%). The second was hypertension (31.5%).

Preoperative DVT was diagnosed in 62 of 505 (12.3%) patients overall. Significantly elevated risks of DVT were found in patients with increased age, medical history of major surgery, RA and medical history of cancer treatment by Fisher's exact test. The mean age of DVT positive patients was significant old compared with that of DVT negative patients (p<0.001). 56.5% (35/62 patients) of the DVT positive group undergone major surgery, but only 34.3% (152/443) of the DVT negative group undergone major surgery (p=0.0011). Although the DVT negative group were 4.7% (21/443) in RA and 9.5% (42/443) in medical history of cancer, the DVT positive group were 12.9% (8/62; p=0.0406) and 22.6% (14/62; p=0.0044), respectively.

Next, multiple linear regression analysis was performed to test the association of DVT with putative risk factors. The analysis showed that increased age (p=0.0043), RA (p=0.0109) and medical history of major surgery (p=0.0203) were the independent risk factor for DVT in this study.

Conclusions Patients admitted to hospital for THA with increased age, RA and medical history of major surgery may be at an increased risk of subsequent DVT.

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.3930